A turbogenerator electric power generation system is generally comprised of a compressor, a combustor including fuel injectors and an ignition source, a turbine, and an electrical generator. Often, the system includes a recuperator to preheat combustion air with waste heat from the turbine exhaust. A recuperator is most efficient if the mass flows through it are evenly distributed. A recuperator also reduces the expansion ratio of the turbine and thus the power extracted by the turbine. Therefore, what is needed is a turbine engine that promotes even mass distribution of the exhaust gas into the recuperator and maximizes the turbine expansion ratio.
In one aspect, the present invention provides a turbine engine comprising a turbine rotationally driven by hot gas to exhaust the gas, a compressor rotationally coupled to the turbine to generate compressed air, an annular combustor for combusting fuel and the compressed air to generate the hot gas, the combustor extending coaxially away from the turbine to form a passage for the turbine exhaust gas therethrough, an annular recuperator surrounding the turbine for transferring heat from the turbine exhaust gas to the compressed air, a surface spaced from the combustor to direct the exhaust gas exiting from the passage into the recuperator, and an elongated structure extending from the surface into the passage toward the turbine to direct the exhaust gas flowing through the exhaust passage.
In another aspect, the elongated structure is generally conical. In other aspects, the structure is spaced from the combustor to form an annular exhaust passage, wherein the exhaust passage may be configured to sustain diffusion of the exhaust gas flowing therethrough. The passage may also be configured for evenly distributing the exhaust gas entering the recuperator.